Method for improving sensitivity of detecting metal ion pollution

The invention provides a method for improving the sensitivity of detecting metal ion pollution, which comprises the following steps of: firstly adopting an isotropic process treatment process with unbiased radio frequency and high pressure, then adopting an anisotropic process treatment process with high-power biased radio frequency and low pressure, or adopting a process condition that the second step is carried out and then the first step is carried out. The distribution of plasmas in the process cavity is improved, so that different metal elements with light and heavy molecular weights are captured at the same time. According to the invention, the plasma can touch the corner of the process cavity by adjusting the gas pressure of the cavity and the radio frequency power on the etching machine table, so that the time condition of metal pollution of the cavity is reflected more truly, the sensitivity and stability of ICPMS detection are greatly improved, and the process requirement of continuous iteration of